The Conservatives have turned to American-style negative campaigning in the by-election battle for Rochester and Strood - with a video attacking Ukip candidate Mark Reckless over development at Lodge Hill.

It is a sign that the final two weeks of the campaign could prove ugly, with mud-slinging between the parties reaching feverish levels ahead of polling day.

Ukip reacted angrily, saying it was a new low in campaigning but the advert was endorsed by Conservative party chairman Grant Shapps.

The 48-second video released by the Conservatives today focuses on what the party claims to be Mr Reckless's U-turn over his opposition to the Lodge Hill development.

It features footage of Mr Reckless speaking in the House of Commons last year in a debate in which he raises concerns expressed by Medway Council about the development of 5,000 homes.

In the debate, he says the council is being frustrated in taking forward the development because of the opposition by Natural England. It has raised concerns about the destruction of a wildlife habitat for nightingales.

In commentary over footage of the debate, the ad says that Mr Reckless had criticised as "absurd" the opposition from Natural England because of the need for new homes.

It contrasts that with his opposition to the development when he defected to Ukip.

Mr Reckless responded in Twitter posts saying that the Conservatives locally had been told not to express any support for the scheme until after the election.

Conservative party chairman Grant Shapps said: "?We're setting the record straight.

"Reckless is claiming he opposed the Lodge Hill development when the opposite is true. He'll say anything to get elected.

"It is in fact the Conservative candidate Kelly Tolhurst who has campaigned against the Lodge Hill development. She has listened to residents' concerns about lack of proper infrastructure for it.

"The residents of Rochester and Strood, and in particular the Hoo Peninsula, deserve to know the truth. Reckless has flip-flopped on this important issue. How can they trust a man who says one thing and does another?'?"

In a statement, Ukip said: "It's funny that they are stooping to a new low in British politics, an attack ad in a by election.

"There again, it's wasting their campaign spending and showing they have nothing positive to offer the people of Rochester and Strood.

"Nothing whatsoever to say about their own involvement in the Lodge hill development. What was that about the return of the nasty party?"

Read the latest by-election blog from our political editor Paul Francis.